How have the courts treated jury affidavits in the past?

Respondents cite to us, as they did to the trial judge, the 1896 case of People v. Conkling, 111 Cal. 616, 627, 44 P. 314, in which case two jurors had performed an experiment with a rifle as to the distance powder marks could be carried. But it is fairly clear that the affidavits were not those of jurors, because they are described as 'affidavits of certain parties,' which is not apt language for describing affidavits of jurors.